Optical measurement devices are known that are used at the outlets from lines for painting bodywork parts in order to verify the appearance of the parts, e.g. their hue, their pinpoint blistering, the leveling of their painting, or their brilliance.
In general, the optical measurement instruments used at the outlet from painting lines are stationary and they see the bodywork parts for inspection pass through their field of view, with the parts usually standing still for a period of sufficient duration to allow the measurement to be performed.
Such instruments are located at a certain distance from the parts to be inspected, which keeps them safe from any risk of being damaged by an untimely impact against a moving part.
Nevertheless, in the most recent painting inspection stations, the measurement instrument is no longer stationary, but is carried by a robot arm that presents it in the proximity of the part to be inspected at different locations thereof in order to take a plurality of measurements at predetermined angles of view.
Under such circumstances, the instrument comes very close to the surface of the part, thereby considerably increasing the risk of collision between the instrument and the part.
The consequences of such a collision can be very severe, particularly given the price of instruments of this kind.